Magnetic sheet transferring apparatus



Dec. 21, 1965 F. E. PARKE ETAL MAGNETIC SHEET TRANSFERRING APPARATUS 4 Sheets-Sheet 1 Filed May '7, 1964 INVENTORS. FRANKLIN E. PARKE HUGH R055 jK/M mM V DO,

their ATTORNEY Dec. 21, 1965 F. E. PARKE ETAL MAGNETIC SHEET TRANSFERRING APPARATUS 4 Sheets-Sheet 2 Filed May 7, 1964 VI 5 RE M m R R 0 MA T S M was 1% .H N M won 1 NH G MU FH B 5 a s s m 8 4 E 8 Dec. 21, 1965 F. E. PARKE ETAL 3,224,757

MAGNETIC SHEET TRANSFERRING APPARATUS Filed May '7, 1964 4 Sheets-Sheet 5 Their ATTORNEY Dec. 21, 1965 F. E. PARKE ETAL 3,224,757

MAGNETIC SHEET TRANSFERRING APPARATUS Filed May '7, 1964 4 Sheets-Sheet 4 I71 I74 64 I78 I74 36 FI-g.I5.

I86 l8892'202 94' I88 I86 INVENTORS FRANKLIN E. PARKE HUGH ROSS ATTORNEY.

. capillary attraction created by the film of oil.

United States Patent 3,224,757 MAGNETIC SHEET TRANSFERRING APPARATUS Franklin Edward Parke and Hugh Ross, Pittsburgh, Pa., assignors to Ropak Manufacturing Co., Pittsburgh, Pa., a corporation of Pennsylvania Filed May 7, 1964, Ser. No. 365,615 25 Claims. (Cl. 271-40) This invention relates to sheet transferring apparatus, and more particularly to apparatus employing magnet means for stacking or destacking sheets of magnetically susceptible material. I

This application is a continuation-in-part of our c0- pending application, now abandoned, Serial No. 256,873, filed February 7, 1963 and entitled, Sheet Transferring Apparatus.

The removal of the top sheet from a stack of sheets is known as destacking. Where the stack is comprised of leveled sheets, the destacking operation presents problems which have been resolved to the satisfaction of the industry. Numerous destacking devices have been invented to resolve these problems.

However, where the stack is comprised of sheets each of which is warped or distorted, the problems are considerably more dilficult. Up to the present no satisfactory device has been presented for efficiently destacking these warped or distorted sheets. The warp or distortion in the sheets may be purposely provided or they may be inherent in the sheet.

An example of a purposely provided distortion will be found in one method used to break the capillary attraction which is present in a stack of oiled sheets. It is normal in the sheet steel making industry to provide each sheet with a protective film of oil or the like. In a stack of these sheets, difficulty is encountered in subsequently trying to separate the sheets because of the The common method of breaking the capillary attraction is to provide a suitable platform having a bar or the like positioned transversely and centrally thereof. When the stack of oiled sheets is placed on this platform, the bar causes the stack to be bowed at its central position. This bowing breaks the capillary attraction.

Other metalworking operations produce semi-finished sheets each of which includes inherent transverse and/ or longitudinal distortions. The transverse distortions may be localized in particular areas of the sheet. The transverse distortions sometime take the form of a transverse bowing which increases the difficulty with which each sheet is picked up and transferred. The transverse bowing may be concave upward in one sheet and concave downward in the next sheet. Examples of processes which produce distorted sheets are annealing process, sheet rolling or forming operations and the like.

Still another example is the warped or bowed sheet produced when a stack of sheets is stored, for an extended period of time, on a support which permits the stack to bow or sag in one or more places.

The operation of destacking is further complicated when the warped sheets are in the final stages of a finishing process and have a finish coating or otherwise finished surface which must not be marred.

The present invention provides novel apparatus which may be used with equal utility in a destacking operation or in a stacking operation, i.e., wherein sheets are placed one on top of the other to form a stack.

Although the present apparatus is particularly useful in destacking warped or distorted sheets, it may be used with equal facility in destacking leveled sheets.

Accordingly, the primary objects of the present invention include:

To provide novel apparatus for stacking or destacking sheets of magnetically susceptible material;

3,224,757 Patented Dec. 21, 1965 To provide novel apparatus for destacking warped or distorted sheets of magnetically susceptible material regardless of whether the warp or distortion is inherent in the sheets or purposely provided therein;

To provide novel apparatus employing magnetic transfer means for transferring single sheets of magnetically susceptible material from a stack of said sheets to a conveyor means for further transfer;

To provide novel apparatus employing magnetic transfer means which conform to the transverse distortions of a sheet of magnetically susceptible material;

To provide novel apparatus employing mangetic transfer means which conform to the longitudinal distortion magnetically susceptible material;

To provide novel apparatus employing magnetic transfer means which are angularly displaceable thereby conforming to the local transverse distortion of a sheet of magnetically susceptible material;

To provide apparatus employing magnetic transfer means having means for effectively varying their strength whereby only single sheets of magnetically susceptible material will be transferred;

To provide novel apparatus for transferring sheets of magnetically susceptible material without marring the finished surface of said sheet; and

To provide novel apparatus having means for breaking the partial vacuum formed between stacked sheets.

These and other objects and advantages of the present invention will become apparent from the following detailed description by reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation view of the present sheet transferring apparatus employed in destacking warped sheets;

FIG. 2 is a view in cross section, taken along the line 2--2 of FIG. 1;

FIG. 3 is a fragmentary side elevation view illustrating one magnetic transfer means of the present invention;

FIG. 4 is a view in cross section, taken along the line 4-4 of FIG. 3, further illustrating the magnetic transfer means of the present invention;

FIG. 5 is a fragmentary side view illustrating an end portion of the magnetic transfer means as viewed from the line 5-5 of FIG. 3;

FIG. 6 is a view in cross section, taken along the line 66 of FIG. 5, further illustrating the end portion of FIG. 5;

FIG. 7 is a fragmentary view illustrating an alterna tive embodiment of the roller means of FIG. 4;

FIG. 8 is a fragmentary cross-sectional view illustrating a further alternative embodiment of the roller means of FIG. 4;

FIG. 9 is a fragmentary side view illustrating a further alternative embodiment of the roller means of FIG. 4;

FIG. 10 is a side elevation view similar to FIG. 1 illustrating an alternative embodiment of the present sheet transferring apparatus employed in stacking sheets of magnetically susceptible material;

FIG. 11 is a fragmentary side elevation view illustrating one embodiment of a magnetic transfer means of the apparatus of FIG. 10;

FIG. 12 is a fragmentary side elevation view illustrating an alternative embodiment of a stripping roll;

FIG. 13 is a fragmentary plan view, partly in cross section, of the stripping roll of FIG. 12 as seen from the line l3-13 of FIG. 12;

FIG. 14 is a view, similar to FIG. 11, illustrating an alternative embodiment of a magnetic transfer means of the apparatus of FIG. 10; and

FIGS. 15 and 16 are cross-sectional views, similar to FIG. 8, illustrating alternative embodiments of means for effectively varying the magnetic strength of the magnetic transfer means.

As hereinbefore stated, the present sheet transferring apparatus find particular utility in destacking warped or distorted sheets. FIG. 1 of the drawings illustrates this use. Referring to FIG. 1, a sheet transferring apparatus is shown and generally indicated by the numeral 10. A stack of sheets 12 rests on an indexingv platform 14 and is positioned beneath the sheet transferring apparatus 10. A first conveyor means 16 is positioned at a discharge end 18 of the sheet transferring apparatus and is used to convey the sheets delivered thereon to other stages of the sheet working process. The sheets in stack 12 are essentially comprised of magnetically susceptible material.

The indexing platform 14 functions to raise the stack of sheets 12 at one-half to one inch increments so that the top sheet is always within easy reach of the sheet transferring apparatus 10.

The first conveyor means 16 is specifically illustrated as comprising a belt-type conveyor. Alternatively, the first conveyor means 16 instead could comprise any suitable type of conveying means, as for example, a rollertype conveyor.

The sheet transferring apparatus 10 generally comprises a magnetic conveyor means 20 having a frame 22 and belt means 24; drive means 26 supported by the frame 22; spaced parallel shafts 28 journalled to the frame 22 and extending transversely therethrough; magnetic transfer means 30 one each connected for limited rotational movement to each of the shafts 28 and on both sides of the magnetic conveyor means 20; connecting means 32 secured to the shafts 28 for rotating all of the shafts 28 in unison; and actuating means 34 secured to the connecting means 32 for forcibly rotating the connecting means 32.

Generally then, the drive means 26 drives the belt -means 24 in a clockwise direction as viewed in FIG. 1.

The magnetic transfer means 30 being secured to the shafts 28 for limited rotational movement thereof, will, when in the position illustrated in FIG. 1, conform to the longitudinal distortions of the stack of sheets 12. The magnetic transfer means 30 are preferably of such strength whereby they will retain thereon only a top sheet 36 of the stack 12. In order to transfer the top sheet 36 to the magnetic conveyormeans 20, actuating means 34 is activated to rotate connecting means 32 in a clockwise direction whereupon the magnetic transfer means 30 will rotate about the rotational axis of the shafts 28 to lift the top sheet 36. The elevated positions of the magnetic transfer means and the top sheet are illustrated in phantom outline and indicated by the numerals 30' and 36', respectively. Thus, the sheet transferring apparatus 10 will move the top sheet 36 from a first position, i.e., a position on top of the stack of sheets 12, to a second position, i.e., a position wherein the sheet is engaged with the lower reach 38 of the belt means 24.

At this point in the transferring operation, the top sheet 36' is engaged with the lower reach 38 of the belt means 24 and within the magnetic field of the magnetic conveyor means 20. This magnetic field will retain the top sheet 36' in transferring engagement with the lower reach 38 of the belt means 24 whereby the top sheet 36 is conveyed toward and onto the first conveyor means 16. A sheet, illustrated in phantom outline and indicated by the numeral 36", is shown on the conveyor means 16.

A detailed description of the elements of the sheet transferring apparatus 10 will now follow with reference to FIGS. 1 to 6, inclusive.

Referring in particular to FIGS. 1, 2 and 3, the frame 22 of the magnetic conveyor means 28, preferably comprises two U-shaped channel members 40 which are maintained spaced apart by means of upper and lower connecting sheets 42, 44, respectively. The channel members 40 and the c nnecting sheets 42, 44 prefera ly comprise sheets formed from material having a low permeability, i.e., non-magnetic material.

Journalled transversely of the ends of the channel member 40 are belt rollers 46 about which the belt means 24 turns.

Mounted on the inner face of the lower connecting sheet 44 is a plurality of magnets 48, preferably of the permanent type, which are arranged in rows extending longitudinally along the conveyor means 20. Each row of magnets 48 includes continuous bars 50, 52 interposed between the magnets 48 and the lower connecting sheet 44. The bars 50, 52 preferably are formed from material having a high permeability and serve to connect similar poles of all the magnets 48 in each row. As for example, the bar 50 connects all the north poles and the bar 52 connects all of the south poles. Hence, the bars 50, 52 spread the magnetic flux lines of the magnets 48 throughout the length of the conveyor means 20. As illustrated in FIG. 2, the magnets 48 are disposed adjacent to the lower reach 38 of the belt means 24 so that the magnetic field or flux lines, illustrated by the dotted lines and generally indicated at 54, extend through the lower reach 38. With this arrangement, a sheet of magnetically susceptible material, which is brought within the magnetic field 54, will be permeated by the field and pulled into engagement with the lower reach 38 to be transferred thereby.

Referring to FIGS. 1 to 6, each of the shafts 28 extends transversely between and through the channel members 40. Journal means 56 rotatably support the shafts 28 on the channel members 40.

The magnetic transfer means 30 each comprise arm 58, stop means 60, and roller means 62 including magnet means 64.

Referring in particular to FIGS. 4, 5 and 6, a projecting shaft end portion 28 extends through a bore 66 in the upper end 68 of the arm 58 in loosely fitting engagement therewith. The arm 58, thus, is freely rotatable about the shaft 28.

As hereinbefore stated, the magnetic transfer means 30 are connected to the shafts 28 for limited rotational movement thereof. To this end, stop means is provided to limit the relative rotation of the arm 58 with respect to the shaft 28. The stop means 60 comprises a collar 70 having a bore 72 through which the shaft end portion 28' extends. The collar 70 is a non-rotatably secured to the shaft end portion 28' by means of a key 74 and a setscrew 76. The collar '70 includes a projection 78 which fits into a recess 80 provided in the end portion 68 of the arm 58. The projection 78 has a shoulder 82 which is spaced from and is adapted to engage a shoulder 84 of the recess 80. As can be seen in FIG. 6, the arm 58, for example, may be rotated for a limited distance to the position illustrated in phantom outline and indicated by the numeral 58'. In this rotated position, the shoulder 84 abuts the shoulder 82 to limit the rotational movement of the arm 58 with respect to the shaft 28. The arm 58 is rotated through an angle indicated at 86 (FIG. 6) which is subtended by the centerlines 88 and 98 of the arms 58, 58', respectively. It should be noted that the angle indicated at 86 is only one half of the total angle through which the arm 58 may move. This should be evident since the arms 58 could rotate in a counter clockwise direction for a distance equal to that shown. It should also be noted that the total angle indicated at 87 (FIG. 3) through which the arm 58 may rotate with respect to the shaft 28 is directly proportional to the spacing of the shoulders 82 and 84. Hence, by increasing thespacing shown, the angle of movement will be increased; while by reducing the spacing shown the angle of move-- ment will be reduced. The purpose of this limited rotational movement will be described later in the specification with reference to FIGS. 1, 2 and 3. It should be evident that the shaft 28 and the arms 58 may be thought of as a carrier for the roller members 62, which carrier Serves in moving the roller means 62 between the aforementioned first and second positions.

Referring in particular to FIGS. 3 and 4, the roller means 62 preferably comprise a roller formed from two complementary cup-shaped members 92, 94 which are connected together by means of a plurality of bar magnets 64. The cup-shaped members 92 and 94 preferably are formed from materials having a high permeability. The cup-shaped members 92, 94 are spaced apart, as at 96, and each connects the similar poles of the 64. As for example, cup-shaped member 92 could be a north pole while cup-shaped member 94 could be the south pole. A cover 97, preferably of resilient material such as rubber, surrounds the outer surface of the roller means 62. The cover 97 serves firstly as an insulating member which limits the force of the magnetic field of the magnets 64 so that only one sheet is attracted; and secondly, to prevent marring the finished surface of the sheets carried thereby. Alternatively, as shown in FIG. 7, an angular disc member 98 may be secured to the outer face of each of the cup members 92, 94. The disc members 98 preferably are formed from suitable plastic materials such as polyurethane, polyethylene, and the like. Alternatively, the disc members 98 may be formed from hard rubbers and the like. In either case, the selected material must not be hard enough to mark the surface of the sheets being transferred.

The outer diameter of the disc members 98 is larger than the outer diameter of the cup shaped members 92, 94. Hence, the disc members serve to maintain the sheet 36 spaced from the cup-shaped members 92, 94. A space 99 thus is provided wherein dust, particles of metal and the like may accumulate. The particles of metal, in particular, will be maintained engaged with the cup-shaped members 92, 94 and hence cannot mar the finished surface of the sheet 36.

It should be evident that other disc members 98 of smaller or larger diameter may be provided. In this manner, the force of the magnetic field provided by the magnets 64 may be controlled, i.e., the sheet 36 will be brought closer to or more spaced from the cup-shaped members 92, 94 thereby either increasing or decreasing the attraction of the magnets 64. In this manner only one sheet will be attracted to the roller means 62'.

A lower end portion 100 of each of the arms 58 includes an outwardly extending support shaft 102. The cupshaped members 92, 94 of the roller means 62 each have a journal element such as the brass bushing 103 extending centrally therethrough. The bushing 103 preferably is press-fitted in the cup-shaped members 92, 94 so that the bushing 103 is an integral part of the roller means 62.

'The bushing 103 has a central bore 104 through which the support shaft 102 extends. The diameter of the central bore 104 is larger than the diameter of the support shaft 102. Therefore, the roller means 62 is freely rotatable about the shaft 102. Furthermore, by virtue of the loose fitting engagement between the shaft 102 and the bushing 103, the position of the roller means 62 is angularly movable relative to the shaft 102 about a centerpoint indicated at 105 in FIG. 4.

This angular movement permits each of the roller means 62 to be displaced into line contact with the upper surface of the sheet 36 (FIG. 2). That is to say, in the instance where that portion of the sheet 36 to be contacted by the roller means 62 is not parallel with the shaft 102, the roller means may be displaced angularly with respect to the shaft 102 and into line contact with the sheet 36. This insures a good firm magnetic grip to be made between the roller means 62 and the sheet 36.

In FIG. 8 there is illustrated an alternative means by which angular displacement of a roller means 62 is made possible. Corresponding numerals will be employed to identify corresponding parts already described.

In this embodiment, a spherical bearing 106 is employed for journalling the roller means 62 to the support shaft 102. The spherical bearing 106 has correspond ing convex and concave spherical surfaces 107 and 108, respectively. The corresponding spherical surfaces 107, 108 permit free rotation of the roller means 62 about the shaft 102 and also angular movement about a centerpoint 106A through an angle indicated at A. Thus, the spherical bearing 106 comprises a unitary journal means permitting the free rotation and angular displacement of the roller means 62.

In FIG. 9 there is illustrated a further alternative means by which angular displacement of a roller means 62" is made possible. Corresponding numerals will be employed to identify corresponding parts already described.

In this embodiment, the roller means 632" is journaled to the shaft 102 only for rotation. The angular displacement is provided by a spherical hearing or ball joint 164 comprising a support member 166 secured to the arm 58 and a ball member 168 forming part of the shaft 102 and engaged in the support member 166 for angular movement through the angle indicated at A.

Referring to FIGS. 1 to 3, inclusive, it will be noted that the limited rotational movement of the arm 58 about the shaft 28, aflorded by the stop means 60, permits the roller means 62 to move through a predetermined vertical distance as indicated at 109 in FIG. 3. It will also be noted that the magnetic transfer means 30 associated with each shaft 23 are free to rotate through the limited distance either in pairs or individually. Thus, it should be obvious that the pair of magnetic transfer means 3 0 of each shaft 28 will conform to the longitudinal distortions of the sheets in the stack of sheets 12 as illustrated in FIG. 1. 0n the other hand, it should be obvious that each magnetic transfer means 30 of each shaft 28 also will conform to the transverse distortions of the sheets 12. This fact is illustrated in FIG. 2 wherein the roller means 62 are shown displaced by a vertical distance indicated at 11.0 which equals the amount of distortion indicated at 112 in the top sheet 36. In this instance, sheet portions 36A and 368 on which the roller means 62 are engaged, are illustrated as being parallel. It should be evident that if the sheet portions 36A and 3613 were not parallel, the roller means 62 would be angularly displaced into line contact with the sheet portions 36A and 36B, as described above.

Referring now to FIGS. 1 and 2, the connecting means 32 serving to rotate all of the shafts 28 in unison, comprises extension arms 114 and connecting bar 116. Each of the extension arms 114 preferably are contiguous at one end with one of the stop members 60 and extends upwardly therefrom. The upper ends of the extension arms 114 are rotatably secured at spaced points to the connecting bar 116.

Referring to FIG. 1, the actuating means 34 is illustrated as comprising a fluid actuated cylinder-and-piston assembly. Alternatively, the actuating means could comprise any suitable means for forcibly rotating the shafts 28, as for example, a rack-and-pinion assembly or a cam mechanism. As illustrated, the actuating means 34 comprises a cylinder 118 having a piston shaft 120 rotatably secured as at 121 to one end 122 of one of the extension arms 114. The cylinder 118 is pivotally secured at its other end as indicated at 124,

Referring again to FIGS. 1, 2 and 3, when the actuating means 34 is activated, the piston shaft 120 will be extended outwardly of the cylinder 118 whereupon the end 122 will be displaced to the position illustrated in phantom outline at 126. Sufficient movement of the end 122 will cause all of the shafts 28 to be rotated through the action of the connecting bar 116 and the extension arms 114 whereupon the magnetic transfer means 30 will be rotated to the position indicated at 30'. As can be seen the top sheet 36 is retained in engagement with the rollers 62 by means of the magnets 64- and thus is moved into engagement with the lower reach 38 of the belt means 24 as indicated at 36'. Since the roller means 62 are rotatably supported on the arms 58, the lower reach 38 serves as means for stripping the sheet 36' from the roller means 62 and thus conveys it to the first conveyor means 16.

It is important to note that the forward motion of the rollers 62 serves two important functions. Firstly, when the arms 58 begin to rotate from their normally lowered position, the rollers 62 will move the top sheet in a forward direction, i.e., longitudinally of the stack 12. This forward motion aids considerably in breaking the partial vacuum formed between the sheets and in breaking the capillary attraction in the case of oiled sheets. Secondly, when the top sheet 36 is elevated by the magnetic transfer means 30, its motion is in the same direction as that of the lower reach 38. Thus, the top sheet 36 is initially accelerated in the direction of belt movement.

It has been stated that the present sheet transferring apparatus may be used with equal facility in a stacking operation. This use is illustrated in FIGS. and 11, inclusive. Corresponding numerals will be employed to identify corresponding parts already described.

In FIG. 10 the sheet transferring apparatus 141 is shown having magnetic transfer means 128 rotatably secured to shafts 28. A first conveyor means 130 is positioned at an entry end 132 of the magnetic conveyor means 26. The sheet transferring apparatus 10 is positioned over a stacking area or platform 134 which is similar to the indexing platform 14. The stacking platform 134 serves to lower the upper surface 135 thereof at one-half to one inch increments. The sheet transferring apparatus 10 is herein used in a stacking operation wherein finished or semi-finished sheets 136 are stacked on the platform 134 to form a stack 138. As before, the sheets 136 are essentially comprised of magnetic susceptible material.

Referring to FIG. 11, the magnetic transfer means 128 includes the arm 58, stop means 60 and roller means 62 including magnets 64 shown in phantom outline. The magnetic transfer means 128 further includes a means for stripping the sheets 136 from the roller means 62 which preferably comprises a non-magnetic stripping roller 140 rotatably secured to an extension 142 of the arm 58. The non-magnetic roller stripping 140 has a diameter which is smaller than the diameter of the roller means 62.

As can be seen from FIGS. 10 and 11, when the sheet 136 is conveyed for a predetermined distance along the magnetic conveyor means 20, the actuating means 34 is activated whereupon the connecting means 32 will rotate all of the shafts 28 in unison. At this time, the magnetic transfer means 128 will pivot downwardly in a counterclockwise direction. The magnets 64 will retain the sheet 136 engaged on the roller means 62. When the magnetic transfer means 128 are lowered to the position indicated in phantom outline at 128, the non-magnetic stripping roller 140' will engage the sheet 136'. Further downward movement of the magnetic transfer means 64 will cause the sheet 136 to be stripped from the roller means 62 by means of the non-magnetic stripping roller 140 and cause the sheet 136' to fall on the stack 138. If desirable, a cushion 143 may be provided at the end of the magnetic conveyor means 20 to serve to stop the longitudinal movement of the sheet 136.

It should be noted in this embodiment, that the magnetic transfer means 128 has two inherent braking actions which aid in slowing down the sheet 136. Firstly, since the pivotal motion of the magnetic transfer means 128 about the shafts 28 is in a backward direction, it opposes the forward motion of the sheet 136. Secondly, the mag netic attraction of the roller 62 provides a drag on the sheets 136 which further aids in slowing down the sheet 136.

It should also be noted that the magnetic conveyor means 20 may also be used as a means for slowing down the sheet 136. In FIG. 11, the channel member 40 has been broken away to show the positions of the magnets 48 and the bar 52 with respect to the lower reach 38. It should be evident that when the sheet 136 is attracted by means of the magnets 48, the lower reach 38 is clamped between the sheet 136 and the lower connecting sheet 44. Thus, when the belt 24 is driven, the clamped portion lower reach 38 Will slide over the lower connecting sheet 44 and produce a sliding friction which must be overcome by the drive means 26. Consequently, if desired, the power to the drive means 26 may be momentarily turned off whereupon the sliding friction, produced by the lower reach 38, will rapidly decelerate the sheet 136. The magnetic transfer means 128 may now be used to dis engage the sheet 136 from the magnetic conveyor means 20 and further decelerate the sheet 136 in the manner heretofore described.

The stripping roller preferably is formed from a soft resilient material such as rubber so that the finished surface of the sheet 136 will not be marred.

Referring now to FIGS. 12 and 13, a stripping roller 144 is shown rotatably supported by a stub shaft 146 on the extension 142 of the arm 58. In this embodiment the stripping roller 144 may be formed from any suitable plastic materials or non-magnetizable metallic materials. In order to prevent the marring of the finished surfaces of the sheets being stacked, the stripping roller 144 is provided with a cover 148 preferably comprising a resilient or soft material such as rubber or the like.

The stripping roller 144 is adapted as another means for decelerating the sheet being transferred. Mounted on the stub shaft 146 is an adjustable brake means 150 comprising spaced washers 152, 153 engaged With the ends of spring member 154 and a nut 156 threaded onto the end of the stub shaft 146. When the not 156 is tightened, the spring member 154 will be compressed to increase the friction between the washer 153 and the stripping roller 144; and when the nut 156 is tightened, the compression of the spring member 154 will be reduced to decrease the friction between the washer 153 and the stripping roller 144. Consequently, the stripping roller 144 is provided with a means for varying the ease with which it may rotate about the stub shaft 146. Hence, when the stripping roller 144 is engaged with a moving sheet, the sheet will be decelerated. It should be evident that the adjustable brake means 150 could be used With equal facility in c0njunction with the stripping roller 140 of FIG. 11.

It has been stated that the stripping roller 140 preferably comprises a non-magnetic roller. Alternatively, the stripping roller 140 could comprise a magnetic roller whose magnetic field is considerably less than the magnetic field of the rollers 62. This alternative magnetic stripping roller would aid in decelerating a sheet since its magnetic field would provide a drag on the moving sheet.

In the case where marring of the surface of the sheets is of no consequence, an alternative embodiment of the magnetic transfer means may be used which is illustrated in FIG. 14. In this embodiment a magnetic transfer means 158 is shown wherein the means for stripping the sheet 136 from the roller means 62 comprises merely an extension 160 of the arm 58. The operation of this embodiment is similar to the embodiment illustrated in FIG. 11. Thus, when the magnetic transfer means 158 is lowered to the position indicated in phantom outline at 158, the extension 160' will engage the sheet 136'. Further downward movement of the magnetic transfer means 153 will cause the sheet 136 to be stripped from the roller means 62 by means of the extension 160.

It should be understood that this embodiment of the sheet transferring apparatus could, with equal facility, be used to stack warped or distorted sheets.

As stated above, the present invention provides means for effectively varying the strength of the magnetic transfer means so as to insure that only one sheet of magnetically susceptible material is transferred at one time, as for example, during a desta-cking operation, In FIGS. 15

9 and 16 there is illustrated a preferred embodiment and an alternative embodiment of the means noted above.

Referring now to FiG. 15, there is illustrated a mag netic transfer means 178 which is similar to the magnetic transfer means 62 of FIG. 8. Accordingly, correpsonding numerals will be employed to identify corresponding parts already described. The magnetic transfer means 1'70 is provided with adjusting means 172 for effectively varying the strength of the magnet means 64. The magnetic transfer means 170 comprises the cup-shaped members 92, 94 which form a roller member 171 and which are journaled to the shaft 102 preferably by means of the spherical bearing 1116. In this embodiment, the spherical bearing 1% preferably is self-lubricating and formed from oil impregnated sintered bronze. Magnet means 64- are positioned between the cup-shaped members 92', 94 as explained above. Each of the cup-shaped members 92, 94' have a lateral wall member 174 extending transversely of the rotational axis 176 of the roller member 171 and a cylindrical wall member 178.

In the preferred embodiment, the adjusting means 172. comprises two resilient, annular discs 18%, 182 each of which is positioned on an externally hub 184 projecting laterally from each of the wall members 174. The resilient discs 188, 182 are engaged with the wall members 174 and are at least coextensive with the wall members 174 and preferably slightly greater in diameter than the wall members 174. Each of the resilient discs 180, 182 has a peripheral surface 186 which is substantially even with the outer cylindrical surface 188 of the roller memher 171. That is to say, the diameter of the resilient discs is at least equal to and preferably slightly greater than the outer diameter of the wall members 174.

Engaged with each of the resilient discs 189, 182 and carried by each of the hubs 184 is a rigid disc or washerlike member 190 whose outer diameter preferably is slightly less than the outer diameter of the wall members 174. The rigid discs 1% preferably are formed from metal. Threaded onto each of the hubs 184 and into engagement with the rigid discs 1% is a relatively large nut 192.

The resilient discs 180, 182 preferably are formed from resilient material, such as rubber, and of a suitable hardness. The hardness of the material used in forming the resilient discs 188, 182 is important from the standpoint of preventing marring the surface of the sheet being transferred. This is especially true when sheets having a finished surface are to be transferred. It should be evident then that the particular physical characteristics of the material depends on the sheets being transferred. The common characteristic of any of the suitable materials is that of being resilient. Since, the discs 180, 182 are resilient, they may be and are compressed in the present adjusting means 172.

For the purpose of illustration, the resilient disc 180 is shown in its normal uncompressed condition while the resilient disc 182 is shown in a compressed condition.

As shown, the peripheral surface 186 of the resilient disc 181) is substantially even with cylindrical surface 188 of the roller member 171. However, by forceful turning of the nut 192, the resilient disc will be compressed as illustrated by the annular disc 182. Since the resilient disc 182 is confined on three sides, upon being compressed, its peripheral surface 186 will flow or be extruded so that the peripheral surface 186 projects beyond the outer cylindrical surface 188 by the distance indicated at 194. It should be evident that the distance by which the peripheral surface 186 projects beyond the cylindrical surface 188 will depend on the amount of compression of the resilient disc 182. It is important to note that the compressive force applied by the nuts 192 is distributed substantially equally throughout the entire area of each resilient disc 18%), 182. The equally distributed compressive force will cause the peripheral surfaces 186 to be projected by the same amount throughout their entire circumferential length. Note that the annular discs 188, 182 are individually compressed simply by turning the nuts 192. Further, the nuts 192, being engaged with the rigid discs 1911 rather than directly on the resilient discs 188, 182, may be easily turned, i.e., the sliding friction between the rigid discs 1% and the nuts 192 is relatively small.

Through the use of a torque-indicating wrench, a predetermined amount of compression may be applied to each of the nuts 19 2. The peripheral surfaces 186 of the resilient discs 188, 182 will be extruded beyond the outer cylindrical surface 188 by any desired distance. As illustrated, the sheet 36 of magnetically susceptible material is spaced from the roller member 171. For relatively light gage sheets, the distance 194 will be a maximum and for relatively heavy gage sheets, the distance 194 will be a minimum. It should be evident that varying the distance 1%, in effect, varies the strength of the magnet means 64. More specifically, at each position relative to the roller member 171, the sheet 36 will be subjected to different magnetic field intensities.

An alternative means by which the effective strength of the magnet means 64 may be varied is illustrated in FIG. 16. Shown therein is a magnetic transfer means which is similar in many respects to the magnetic transfer means 170 of FIG. 15. Accordingly, corresponding numerals will be employed to identify corresponding parts already described.

Each of the cup-shaped members 92', 94 is provided with a laterally projecting hub 196 which in this embodiment is not threaded. The resilient annual discs 180, 182 are slipped over the hubs 1% and into engagement with the wall members 174. A washer-like member 198 is slipped over each of the hubs 196 and into engagement with the resilient discs 188, 182. Each of the washer-like members 198 has an opening 200 whose diameter is slightly greater than the outer diameter of the hub 196 so that the washer-like members 198 are freely slideable on the hubs 196. Each of the washerlike members 198 han an outer diameter which is slightly less than the outer diameter of the wall members 174. A plurality of through-bolts 202 (only one visible) extend through the washer-like members 188, the resilient discs 18%, 182 and the wall members 174-. The throughbolts 202 preferably have a square or other suitably shaped head 204 which is non-rotatably held in a correspondingly shaped well 206 formed in one of the washerlike members 198. The through-bolts: 202 have a threaded end portion 208 on which is threaded a nut 2111. The through-bolts 202 are positioned between adjacent ones of the magnet means 64. The number of the through-bolts 202 which are employed will depend on the size of the magnetic transfer means 178.

Since the nuts 210 must be turned individually, the resilient discs 180, 182 will be compressed in parts, i.e., in the region of the nut 211) being turned. However, both of the resilient discs 181 182 are compressed simultaneously through the cooperative action of the throughbolt 292 and the nut 210. It should be evident that by using a torque-wrench, for example, all of through bolts 202 and nut 210 may be made to apply substantially equal amounts of compressive force throughout the entire areas of both the resilient discs 180, 182. Consequently, the peripheral surfaces 186 will be caused to project beyond the outer surfaces 188 by the same amount throughout their entire circumferential length.

It should be evident from the foregoing detailed description that the present invention provides novel apparatus; for stacking or destacking warped or distorted sheets of magnetically susceptible material; which employs magnetic transfer means which are capable of conforming to the longitudinal as well as the transverse distortions of the sheets of magnetically susceptible materials which will transfer finished sheets without marring the finished surface thereof; and which is capable of breaking the partial vacuum formed between stacked sheets.

Although the invention has been shown in connection with certain specific embodiments, it will be readily ap parent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention.

We claim as our invention:

1. In apparatus for transferring single sheets of magnetically susceptible material, the combination comprising:

a carrier;

a plurality of spaced magnetic transfer means supported by said carrier for reciprocal movement between a first position and a second position, said magnetic transfer means comprising roller members each including magnet means for attracting a single sheet of magnetically susceptible material to said roller members;

journal means supporting each of said roller members for free rotation about spaced substantially parallel axes;

means supporting each of said roller members for individual free angular displacement relative to said carrier whereby each of said roller members when in said first position are displaced into contact with the surface of said single sheet of magnetically susceptible material at a plurality of points thereon;

means for moving said spaced magnetic transfer means as a unit to said first position wherein said single sheet of magnetically susceptible material is attracted into engagement with said roller members and then for moving said magnetic transfer means and said single sheet as a whole to said second position; and

means for moving said single sheet when in said second position in a direction perpendicular to the axes of said roller members to discharge said sheet from said apparatus, said magnetic transfer means being stationary with respect to said carrier during discharge of said sheet.

2. In apparatus for transferring single sheets of magnetically susceptible material, the combination comprising:

a carrier;

a plurality of spaced magnetic transfer means supported by said carrier for reciprocal movement between a first position and a second position, said magnetic transfer means comprising roller members each including magnetic means for attracting a single sheet of magnetically susceptible material to said roller members;

unitary means for connecting said roller members to said carrier for individual free rotation about spaced substantially parallel axes and for individual free angular displacement relative to said axes whereby each of said roller members when in said first position are displaced into contact with said single sheet of magnetically susceptible material at a plurality of points thereon;

means for moving said spaced magnetic transfer means as a unit to said first position wherein said single sheet of magnetically susceptible material is attracted into engagement with said roller members and then for moving said magnetic transfer means and said single sheet of magnetically susceptible material as a whole to said second posit-ion; and

means for moving said single sheet of magnetically susceptible material when at said second position in a direction perpendicular to the axes of said roller members to discharge said single sheets from said apparatus, said magnetic transfer means being stationary with respect to said carrier during discharge of said sheet.

3. In apparatus for transferring single sheets of magnetically susceptible material,

prising:

netically susceptible material, the combination comprising:

a carrier;

a plurality of spaced magnetic transfer means supported on said carrier for reciprocal movement from a first position to a second position spaced from said first position, said magnetic transfer means comprising roller members including magnet means for maintaining a single sheet of magnetically susceptible material engaged with said roller members during movement thereof from said first position to said second position;

shaft means extending from said carrier, one each supporting each of said roller members;

journal means connecting each of said roller members to one of said shaft means in loosely fitting relation therewith, said roller members being freely rotatable about said shaft means and being angularly displaceable relative to said carrier and into contact with said single sheet;

means for moving said spaced magnetic transfer means as a unit to said first position wherein each of said roller members attracts said single sheet into engagement therewith and then to said second position; and

means for moving said single sheet when in said second position in a direction perpendicular to the axes of said shaft means for discharging said single sheet from said apparatus.

4. In apparatus for transferring single sheets of magnetically susceptible material, the combination comprising! a carrier;

a plurality of spaced magnetic transfer means supported on said carrier for reciprocal movement from a first position to a second position spaced from said first position, said magnetic transfer means comprising roller members including magnet means for maintaining a single sheet of magnetically susceptible material engaged with said roller members during transfer thereof from said first position to said second position;

shaft means extending from said carrier, one each supporting each of said roller members;

spherical bearings, one each connecting each of said roller members to said shaft means, said roller members being freely rotatable about the axis of said shaft means and being angularly displaceable relative to said carrier and into contact with said single sheet;

means for moving said spaced magnetic transfer means as a unit to said first position wherein each of said roller members attracts said single sheets into engagement therewith and then to said second position; and

means for moving said single sheet when in said second position in a direction perpendicular to the axes of said shaft means for discharging said single sheet from said apparatus.

5. In apparatus for transferring single sheets of magthe combination coma plurality of shafts; means rotatably supporting said shafts in spaced substantially parallel relation; spaced-apart magnetic transfer means connected to each of said shafts for arcuate movement about said shafts, each of said magnetic transfer means comprising:

an arm connected to said shaft for rotation therewith, and roller means rotatably connected to said shaft and including magnet means for maintaining one of said sheets of magnetically susceptible material engaged with said roller means; means for forcibly rotating said shafts whereby said magnetic transfer means are moved as a unit to transfer said one of said sheets of magnetically susceptible material as a whole from a first position to a second position; and

stripping means adjacent to said second position for disengaging said one of said sheets from said roller means.

6. In apparatus for transferring single sheets of mag netically susceptible material, the combination comprising:

a plurality of shafts;

means rotatably supporting said shafts in spaced substantially parallel relation; 1 spaced-apart magnetic transfer means connected to each of said shafts for arcuate movement about said shafts, each of said magnetic transfer means comprising:

an arm connected at one of its ends to each of said shafts and freely rotatable thereon, roller means connected to the other end of said arm for rotation about an axis substantially parallel with said shafts and including magnet means for maintaining one of said sheets of magnetically susceptible material engaged with said roller means, and stop means rigidly connected to said shaft for limiting the angular movement of said arm about said shaft, each said arm of each of said shafts being angularly displaceable with respect to the other of said arms of the same shaft whereby said roller means will conform to the transverse distortions of said one of said sheets of magnetically susceptible material;

means for forcibly rotating said shafts whereby said magnetic transfer means are moved as a unit to transfer said one of said sheets of magnetically susceptible material from a first position to a second position; and

stripping means adjacent to said second position for disengaging said one of said sheets of magnetically susceptible material from said roller means.

7. The combination of claim 6 including journal means connecting said roller means to said arm, said roller means being freely rotatable and being freely angularly displaceable relative to said arm.

8. *In apparatus for transferring a single sheet of magnetically susceptible material from a warped stack of sheets of magnetically susceptible material to a first conveyor means, said apparatus comprising a first conveyor means, second conveyor means supported above said warped stack of sheets and including a frame operably supporting a belt means, said belt means having a lower reach maintained spaced from and substantially parallel to said warped stack of sheets, means for driving said 'belt means, and conveyor magnet means associated with said belt means for maintaining said single sheet in transferring engagement with the said belt means, said first conveyor means being disposed at the discharge end of said second conveyor means, the improvement comprising:

spaced parallel shafts extending transversely through and journalled to said frame; pairs of magnetic transfer means, each pair being connected to a common shaft, each of said magnetic transfer means comprising:

an arm rotatably connected to said common shaft, roller means disposed below said lower reach of said belt means and resting on the top sheet of said warped stack of sheets, said roller means being rotatably secured to said arm and including magnet means for maintaining the said roller means in engagement with the top sheet of said warped stack of sheets, and stop means rigidly secured to said common one of said shafts for limiting the angular movement of said arm about the shaft, each said arm being angularly displaceable with respect to the other said arm whereby each of said pairs of magnetic transfer means will conform to the transverse distortions of the top sheet of said warped stack of sheets and said pairs of magnetic transfer means will conform to the longitudinal distortions of the top sheet of said warped stack of sheets; and

means for forcibly rotating said spaced parallel shafts in unison whereby said pairs of magnetic transfer means are moved as a unit to transfer said single sheet into engagement with said second conveyor means for subsequent transfer thereby to said first conveyor means.

9. The combination of claim 8 wherein said arm of each said magnetic transfer means is pivotal in the direction of travel of said lower reach.

10. In apparatus for transferring a single sheet of magnetically susceptible material from conveyor means to a stacking area, said apparatus comprising conveyor means supported above said stacking area and including a frame operably supporting a belt means, said belt means having a lower reach maintained spaced from and substantially parallel to a surface of said stacking area upon which said single sheet will be stacked, means for driving said belt means, and conveyor magnet means associated with said belt means for maintaining the said single sheet in transferring engagement with the said belt means, the combination comprising:

spaced parallel shaft extending transversely through and journalled to said frame;

pairs of magnetic transfer means, each pair being connected to a common shaft, each of said magnetic transfer means comprising:

an arm rotatably connected to said common shaft, roller means disposed above the said lower reach of said belt means and adapted to engage the single sheet being transferred by said conveyor means, said roller means being rotatably secured to said arm and including magnet means for maintaining said roller means in engagement with the single sheet being transferred by said conveyor means, stop means rigidly secured to said common shaft for limiting the angular movement of said arm about the said common shaft, each said arm being angularly displaceable with respect to the other said arm whereby each of said pairs of magnetic transfer means will conform to the transverse distortions of the single sheet of material being transferred by said conveyor means and all of said pairs of magnetic transfer means will conform to the longitudinal distortions of the single sheet being transferred by said conveyor means, and stripping means secured to each said arm for stripping the single sheet of magnetically susceptible material from said roller means; and means for forcibly rotating said spaced parallel shafts in unison whereby said pairs of magnetic transfer means are moved as a unit to disengage the single sheet of magnetically susceptible material from said conveyor means and said stripping means are engaged with said single sheet to strip said single sheet from said roller means for stacking on said surface of said stacking area.

11. The combination of claim 10 wherein said arm of each said magnetic transfer means is pivotal in a direction which is counter to the travel of said lower reach.

12. The combination of claim 10 including means for momentarily deenergizing said means for driving said belt means whereby said conveyor magnet means will decelerate the single sheet being transferred.

13. In apparatus for transferring single sheets of mag netically susceptible material, the combination comprismg:

a shaft;

spaced-apart magnetic transfer means connected to means, said second magnetic roller having a magnetic field which is insuificient to support said one of said single sheets of magnetically susceptible material. 17. In apparatus for transferring single sheets of magshaft for rotation therewith, each of said magnetic netically susceptible material, the combination compristransfer means comprising:

an arm connected to said shaft for rotation therewith; and roller means rotatably connected to said arm and including magnet means for maintaining one of said single sheets of magnetically susceptible material in engagement with said roller means; means for forcibly rotating said shaft whereby said magnetic transfer means are moved as a unit to transfer said one of said single sheets of magnetically susceptible material from a first position to a second position; and stripping means for disengaging said one of said single sheets of magnetically susceptible material from said roller means, said stripping means comprising an end portion of said arm.

14. In apparatus for transferring single sheets of magnetically susceptible material, the combination comprismg:

a shaft;

spaced-apart magnetic transfer means connected to said shaft for rotation therewith, each of said magnetic transfer means comprising:

an arm connected to said shaft for rotation therewith; and roller means rotatably connected to said arm and including magnet means for maintaining one of said single sheets of magnetic susceptible material in engagement with said roller means; means for forcibly rotating said shaft whereby said magnetic transfer means are moved as a unit to transfer said one of said single sheets of magnetically susceptible material from a first position to a second position; and

stripping means for disengaging said single sheet of magnetically susceptible material from said roller means, said stripping means comprising a second roller spaced from said roller means and rotatably secured to an end portion of said arm, said second roller having a diameter which is smaller than the diameter of said roller means.

15. The combination of claim 14 including adjustable brake means operatively connected to said second roller for varying the ease with which said second roller may rotate.

16. In apparatus for transferring single sheets of magnetically susceptible material, the combination comprismg:

a shaft;

spaced-apart magnetic transfer means connected to said shaft for rotation therewith, each of said magnetic transfer means comprising:

an arm connected to said shaft for rotation therewith; and roller means rotatably connected to said arm and including magnet means for maintaining one of said single sheets of magnetically susceptible material in engagement with said roller means; means for forcibly rotating said shaft whereby said magnetic transfer means are moved as a unit to transfer said one of said single sheets of magnetically susceptible material from a first position to a second position; and stripping means for disengaging said single sheet of magnetically susceptible material from said roller means, said stripping means comprising a second magnetic roller spaced from said roller means and rotatably secured to an end portion of said arm, said second magnetic roller having a diameter which is smaller than the diameter of said roller ing:

a shaft; spaced-apart magnetic transfer means connected to said shaft for rotation therewith, each of said magnetic transfer means comprising:

an arm rotatably connected at one of its ends to said shaft, roller means rotatably connected to the other end of said arm and including magnet means for maintaining one of said single sheets of magnetically susceptible material in engagement with said roller means, and stop means rigidly secured to said shaft for limiting the angular movement of said arm about said shaft, each said arm being angularly displaceable with respect to the other said arm whereby said magnetic transfer means will conform to the transverse distortions of said one of said single sheets of magnetically susceptible material; and means for forcibly rotating said shaft whereby said magnetic transfer means are moved as a unit to transfer said one of said single sheets of magnetically susceptible material from a first position to a second position.

18. In a magnetic roller for use in transferring single sheets of magnetically susceptible material, said roller being supported for free rotation about its central axis and having lateral wall members extending transversely of said central axis and an outer cylindrical surface, and means within said roller for producing a magnetic field emanating from said roller, the improvement comprising:

resilient discs, one each engaged with each of said wall members, the radius of said resilient discs being at least equal to the radius of said cylindrical surface when said resilient discs are in an uncompressed condition;

rigid discs, one each engaged with each of said resilient discs, said rigid discs having an outer diameter which is less than the outer diameter of said wall members; and

means for displacing said rigid discs toward said wall members to compress said resilient discs whereby the peripheral surfaces of said resilient discs are extruded and project radially beyond said cylindrical surface, the peripheral surfaces of said resilient discs when in their radially projected position being adapted to engage and maintain a single sheet of magnetically susceptible material spaced apart from said roller.

19. The improvement of claim 18 including hubs, one

'' each projecting outwardly from each of said wall members through said resilient discs and beyond saidrigid discs, said hubs cooperating with said wall members and said rigid discs to confine the extrusion of said resilient discs in a radially outward direction.

20. In a magnetic roller for use in transferring single sheets of magnetically susceptible material, said roller being supported for free rotation about its central axis and having lateral wall members extending transversely of said centnal axis and an outer cylindrical surface, and means within said roller for producing a magnetic field emanating from said roller, the improvement comprising:

externally threaded hubs, one each projecting outwardly from each of said wall members;

resilient, annular discs, one each positioned on each of said hubs and engaged with the adjacent wall member, the radius of said annular discs being at least equal to the radius of said cylindrical surface when said annular discs are in an uncompressed condition; washer-like members, one each positioned on each of said hubs and engaged with the resilient disc carried by said hub, said washer-like members having an outer diameter which is less than the outer diameter of said wall members; and

a pair of nuts, one each threaded on each of said externally threaded hubs, said nuts being movable toward said Wall members for individually compressing said resilient annular discs whereby the peripheral surfaces of said annular discs are extruded and project radially beyond said cylindrical surface, the peripheral surfaces of said annular discs when in their radially projected position being adapted to engage and maintain a single sheet of magnetically susceptible material spaced apart from said roller.

21. In a magnetic roller for use in transferring single sheets of magnetically susceptible material, said roller being supported for free rotation about its central axis and having lateral wall members extending transversely of said central axis and an outer cylindrical surface, and means within said roller for producing a magnetic field emanating from said roller, the improvement comprising:

a pair of hubs, one each projecting outwardly from each of said wall members;

resilient, annular discs, one each positioned on each of said hubs and engaged with the adjacent wall members, the radius of said annular discs being at least equal to the radius of said cylindrical surface when said annular discs are in an uncompressed condition;

washer-like members, one each positioned on each of said hubs and engaged with the resilient disc carried by said hub, said washer-like members having an outer diameter which is less than the outer diameter of said wall members;

a plurality of angularly spaced bolts extending through all of said Washer-like members, said annular discs and said wall members, each of said bolts having a head engaged with one of said washer-like members; and

a plurality of nuts threaded onto the projecting ends of said bolts;

said bolts and nuts comprising means for displacing said washer-like members simultaneously toward said wall members for compressing said resilient annular discs whereby the peripheral surfaces of said annular discs are extruded and project radially beyond said cylindrical surface, the peripheral surfaces of said annular discs when in their radially projecting position being adapted to engage and maintain a single sheet of magnetically susceptible material spaced apart from said roller.

22. In apparatus for transferring single sheets of mag netically susceptible material, the combination comprising:

a plurality of shafts;

means rotatably supporting said shafts in spaced, parallel relation;

spaced-apart magnetic transfer means, one each connected to each end of each of said shafts for arcuate movement therewith between a first position and a second position, each of said magnetic transfer means comprising:

an arm connected at one end of said shaft and rotatable therewith,

a magnetic roller journaled to the other end of said arm for rotation about a rotational axis extending perpendicularly from said arm, said roller member having a pair of Wall members extending transversely of said rotational axis and a cylindrical outer surface,

magnet means within said roller member for pro: ducing a magnetic field emanating from said roller member,

resilient discs, one each engaged with each of said wall members, said resilient discs being at least coextensive With said wall members when in an uncompressed condition, each of said resilient discs having a peripheral surface; rigid discs, one each engaged with each of said resilient discs, said rigid discs having an outer diameter which is less than the outer diameter of said wall members; and means for moving said rigid discs toward said wall members to compress said resilient discs whereby said peripheral surfaces are extruded and project radially beyond said cylindrical surface, said peripheral surfaces when in their radially projected position being adapted to engage and maintain a single sheet of magnetically susceptible material spaced apart from said roller member; means for forcibly rotating said shafts as a unit whereby said magnetic transfer means are moved to said first position to engage said single sheet of magnetically susceptible material and then for moving said magnetic transfer means and said single sheet as a whole to said second position; and stripping means adjacent to said second position for disengaging said single sheet from said roller members.

23. In a magnetic roller for use in transferring single sheets of magnetically susceptible material, said roller being supported for free rotation about its central axis and having lateral wall members extending transversely of said central axis and an outer cylindrical surface, and means within said roller for producing a magnetic field emanating from said roller, the improvement comprising:

resilient annular members, one each engaged with each of said wall members, the radius of said resilient annular members being at least equal to the radius of said cylindrical surface when said resilient annular members are in an uncompressed condition;

rigid discs, one each engaged with each of said resilient annular members, said rigid discs having a radius which is less than the radius of said Wall members; and

individual means for moving each of said rigid discs separately toward said wall members to compress said resilient annular members whereby the peripheral surfaces of said resilient annular members are extruded and project radially beyond said cylindrical surface, the peripheral surfaces of said resilient annular members when in their radially projected position being adapted to engage and maintain a single sheet of magnetically susceptible material spaced apart from said roller.

24. In a magnetic roller for use in transferring single sheets of magnetically susceptible material, said roller being supported for free rotation about its central axis and having lateral wall members extending transversely of said central axis and an outer cylindrical surface, and means within said roller for producing a magnetic field emanating from said roller, the improvement comprising:

resilient annular members, one each engaged with each of said wall members, the radius of said resilient annular members being at least equal to the radius of said cylindrical surface when said resilient annular members are in an uncompressed condition;

rigid discs, one each engaged with each of said resilient annular members, said rigid discs having a radius which is less than the radius of said wall members; and

unitary means for displacing said rigid discs simultaneously toward said wall members to compress said resilient annular members whereby the peripheral surfaces of said resilient annular members are extruded and project radially beyond said cylindrical surface, the peripheral surfaces of said resilient annular members when in their radially projected posi tion being adapted to engage and maintain a single sheet of magnetically susceptible material spaced apart from said roller.

25. In a magnetic roller for use in transferring single sheets of magnetically susceptible material, said roller being supported for free rotation about its central axis and for angular displacements relative to said central axis, said roller having an outer cylindrical surface and means Within said roller for producing a magnetic field emanating from said roller, the improvement comprising:

spaced, resilient annular members carried by said roller,

the radius of said members being at least equal to the radius of said roller When said members are in an uncompressed condition; and

means for compressing said members whereby their rim surfaces are extruded and project radially beyond said cylindrical surface, the rim surfaces of said members when in their radially projected position being adapted to engage and maintain a single sheet roller.

References Cited by the Examiner UNITED STATES PATENTS Feist 308-18 Morgan 226-175 X Lincoln 271-18 Clauss 198-41 Moore 198-41 Hathorn 308-18 X Crot 308-18 Fusaroli 29-123 15 M. HENSON WOOD, JR., Primary Examiner.

ROBERT B. REEVES, Examiner. 

4. IN APPARATUS FOR TRANSFERRING SINGLE SHEETS OF MAGNETICALLY SUSCEPTIBLE MATERIAL, THE COMBINATION COMPRISING: A CARRIER; A PLURALITY OF SPACED MAGNETIC TRANSFER MEANS SUPPORTED ON SAID CARRIER FOR RECIPROCAL MOVEMENT FROM A FIRST POSITION TO A SECOND POSITION SPACED FROM SAID FIRST POSITION, SAID MAGNETIC TRANSFER MEANS COMPRISING ROLLER MEMBERS INCLUDING MAGNET MEANS FOR MAINTAINING A SINGLE SHEET OF MAGNETICALLY SUSCEPTIBLE MATERIAL ENGAGED WITH SAID ROLLER MEMBERS DURING TRANSFER THEREOF FROM SAID FIRST POSITION TO SAID SECOND POSITION; SHAFT MEANS EXTENDING FROM SAID CARRIER, ONE EACH SUPPORTING EACH OF SAID ROLLER MEMBERS; SPHERICAL BEARINGS, ONE EACH CONNECTING EACH OF SAID ROLLER MEMBERS TO SAID SHAFT MEANS, SAID ROLLER MEMBERS BEING FREELY ROTATABLE ABOUT THE AXIS OF SAID SHAFT MEANS AND BEING ANGULARLY DISPLACEABLE RELATIV TO SAID CARRIER AND INTO CONTACT WITH SAID SINGLE SHEET; 